Two Iraqi tanks were spotted and pursued, and at one point Marine artillery returned Iraqi fire.

But the main impediments to the convoy's progress appeared to be occasional flocks of sheep and herds of goats and camels. Marines clambered down from their tanks and trucks and shooed the animals out of the way.

At one point, Marines found about a dozen Iraqi mortar shells in a desert bunker that appeared capable of delivering chemical weapons, but were carrying none, sources told CNN.

As the supply line passed through tiny towns and villages, Iraqi children ran after the trucks, and were sometimes rewarded when Marines in light-armored vehicles threw them water and military-issued meals-ready-to-eat.

Outside the towns, several farmers and shepherds waved to the Marines and appeared happy to see the U.S. forces.

At one point, a ragtag band of 46 Iraqi soldiers -- some wearing mismatched uniforms, some barefoot, some wearing civilian clothes -- surrendered to the U.S. forces. Interpreters interviewed them and the military was trying to come up with a plan to process them as prisoners of war.

They appeared to be from the 51st Iraqi mechanized unit out of Basra.

The convoy also sent out Marine teams to scout the surrounding area for the presence of more Iraqi soldiers.

Military radar showed the convoy as a near-solid line headed north from southern Iraq

Some Iraqi civilians were stopped, searched for weapons and allowed to go home.

Some said they had been simply going home to their families in the area when they came across the U.S. forces and surrendered.